Feeder for particulate material



April 3, 1965 H. MITCHELL 3,178,236

FEEDER FOR PARTICULATE MATERIAL Filed April 4, 1963 2 Sheets-Sheet 1 Jzrls A TTORNE Y INVENTOR. HARM MN MITCHELL.

April 13, 1965 H. MITCHELL FEEDER FOR PARTICULATE MATERIAL 2 Sheets-Sheet 2 Filed April 4, 1965 INVENTOR. H/l/eTMA/V MITCHELL BY M Kim.

United States Patent T 3,178,235 FEEDER FOR PARTTCULATE MATERKAL Hartman Mitchell, Pittsbnrgh,Pa., assignor to Coppers Company, Inc s corporation of Delaware Filed Apr. 4, 1963, Ser; No. 270,628 6 illaimsi ((-31. 302-49) This invention relates to an improved apparatus for the injection of particulate material into metallurgical furnaces.

This invention presents an improvement over the invention described in co-pending. application, Serial No. 231,079, filed October 17, 1962, by Elwood V. Schulte and Elliott Freston and assigned to the assigriee of the present application. The coal feeder described in the aforementioned application, Serial No. 231,079 had certain disadvantages. he seal ring must maintain a pressure on the oil side of the seal ring greater than the pressure at the pockets of the feeder wheel of the pump wher the coal'is blown by a gas (air) out of the pockets of the feeder wheel. The seal ring showed a tendency to swell after exposure to sealing oil with the result that the seal ring would not lie tightly against the sealing surface and the seal on the pump was lost. It was extremely tedious and difficult to assemble the pump with the seal ring in place because of the flexibility of the material of which the seal ring was made.

The present invention solves these problems by providing an improved feeder for particulate material and a simplified process for assembling the improved feeder.

In accordance with the invention there is provided a feeder for particulate material which comprises a peripherally pocketed rotary feeder wheel mounted for rotation in an annular housing. The sides of the rotary feeder wheel are enclosed with end plates, and wear plates are located between each of tie end plates and the rotary feeder wheel. The annular housing has a solids entrance at the top thereof, and the wear plates and end plates have aligned air inlet and discharge openings which register with the pockets of the feeder wheel. The rotary feeder wheel has an annular groove on each side thereof and each of the grooves is adapted to have a seal ring secured therein. The wear plate is substantially discshaped with an annular shoulder thereon which annular shoulder contacts the feeder wheel leaving a space between the feeder wheel and the wear plate. Each wear plate and end plate has an aperture therein for the insertion of a sealing fluid such as oil, into the space between the feeder wheel and the Wear plate. A seal ring is esmented in each of the grooves of the feeder wheel and each seal ring has a flange which extends outwardly of the side of said feeder wheel which flange is adapted to coact with the shoulder of the wear plate to form a seal between the feeder Wheel and the wear plate. In this manner the space between the rotor and the wear plates is effectively sealed to prevent leakage of air from the pockets of the rotary feeder wheel through the feeder. To maintain the seal in place, an expandable ring is spaced on the inside of the flange of the seal ring and the expandable ring is allowed to expand and urge t e flange against the annular shoulder of the wear plate. In an alternate embodiment of the invention a spacer ring is positioned between the expandable ring and the flange of the seal ring to aid in maintaining an adequate seal.

The following description of the invention is described with reference to the accompanying drawings in which:

FIGURE 1 is a vertical longitudinal cross-sectional View of the coal feeder of the invention,

FIGURE 2 is a partial transverse cross-sectional View of the coal feeder of the invention,

FIGURE 3 is an enlarged view of the portion of the coal feeder showing the seal assembly,

3,173,235 Patented Apr. 13,. 1965 FIGURE 4 is an enlarged view of an alternate embodiment of the seal assembly,

FIGURE 5 is an isometric View of the expandable ring of the seal assembly in its compressedposition,

FIGURE dis a partial isometric view of the expandable ring in its expanded position.

The improved coal feeder 34- (FIGURE 1) will be seen to be comprised generally of a body or rotor housing 113%; end members 192,194, section 1%2 forming the outlet end of the pump and section 104 beingthe air intake end of'the pump; a feed hopper 116 anda peripherally pocketed rotary feeder wheel 196 having teeth 1138, pockets 199, and shaft 110.

The rotor housing 160 has a generally cylindrical body provided with an extended upper section 118 having a flat top. The sides of the rotary feeder Wheel 196 are enclosed with end plates 102, 1194 and wear plates 122, 124 are located between each of the end plates and the rotary feeder wheel. The annular housing 1% has a solids entrance at the top thereof, and the wear plates 122, 124 and end plates 132, 164 have aligned air inlet and discharge openings 1 54', 146 which register with the pockets 199 of the feeder wheel; The rotary feeder wheel has an annular groove on each side thereof and each of the grooves is adapted to have a seal ring 126, 128'secured therein. The wear plates 122, 124 are substantially disc-shaped with annular shoulders 123, 125" thereon which annular shoulders contact the feeder wheel 1196 leaving a space 127 between the feeder wheel 1% and the wear plates. Each wear plate and end plate has an aperture 147, 143, 149, 15% therein for the insertion of oil into the space 127 between the feeder wheel lihrand the wear plates. The foregoing is described in greater detail in co-pending application Serial No. 231,079.

In accordance with this invention a seal ring 126, 128 is secured in each of the grooves of the feeder wheel 1%. Those seal rings 126, 123 are provided to prevent leakage of pressure air through the coal feeder. The seal rings 126 (FIGURE 3) comprise ring-shaped members having an outer periphery 13d and an inner periphery 132 the distance between the outer periphery 13d and the inner periphery 132 being greater than the thickness of the ring. Flanges 134, 136 are provided which extend from each of said outer periphery and said inner periphery, the flange 134 from said outer periphery extending further than the flange 136 from said inner periphery. Each flange 134 extends outwardly of the side of said feeder wheel lhnndisadaptedto coact with the shoulder 123 of the wear plate 122 to form a seal between the feeder wheel 1-06 and the wear plate 122. This type of seal ring effectively seals the pump whereby the high pressure existent in pockets 1&9 between teeth 1% of coal feeder wheel 166 does not leak through the coal feeder 34 to the atmosphere and entrance of solids into the spaces between the rotor faces and the Wear plate is prevented. In this manner the space between the rotor 186 and the wear plates is effectively, sealed to prevent leakage of air and particulate material from the Pockets 109 of the rotary feeder wheel through the'feeder.

To maintain the seal, anexpandable ringis spaced on the inside of the flange 134 of the seal ring 125 and the expandable ring 156 is allowed to expand and urge the flange 134 against the annular shoulder 123 of the wear plate 122. The ring thus provides a peripheralforce against the seal. The ring may be of conventional. type, for example, a garter spring. As illustrated herein, however, the ring is a split ring 156 havingstepped portions 157, 158 (FIGURES 5 and 6).

The ring can be compressed and locked in the compresed position (FIGURE 5) with a rod 159 inserted through drilled holes 160-, 161 in stepped portions 157', 158 of the expandable ring. The compressed expandable ring is installed inside the flange on the seal ring while compressed. The wear plates 122, 124 and end members 102, 104 are then secured to the annular housing 1% with the rods 159, which are securing the expandable rings in compressed form, extending through the oil holes 147,

148, 149, 150 in the wear plates and end members. The rods 159 are then removed thereby permitting the expandable ring to expand against the flange 134 of the seal ring to urge the flange of the seal ring against the shoulder of the wear plate.

In an alternate embodiment of the invention a spacer ring 163 (FIGURE 3) is positioned between the expandable ring 156 and the flange 134 of the seal ring to aid in obtaining an adequate seal. The seal ring 126 is cemented into the annular groove in the rotary feeder wheel 1155. In the alternate embodiment shown in FIGURE 4, the inner flange 136 of the seal ring is omitted and the seal ring 226 is secured in place by means of a bracket 228 having a shoulder 230 which coacts with the seal ring 225 to hold the seal ring in place. Bracket 228 is secured to the rotary feeder wheel 106 by suitable means such as a plurality of screws 232. The seal ring 226 is kept from slipping by means of dowels 236 which are installed through the seal ring and the rotary feeder wheel. The flange 234 of seal ring 22-5 cooperates with expandable ring 156 in the same manner as the embodiment shown in FIG- URE l.

The specific design of the seal 126, 226 affords a longer life to the coal feeder, requires less maintenance, and gives better sealing action than any seal design heretofore known. The seal ring may be of conventional material to have proper resiliency to effect the seal. Suitable mate rials include neoprene, Teflon (polytetrafluoroethylene), Teflon having fibre glass or finely divided metal such as copper or bronze incorporated therein, or a butadieneacrylonitrile copolymer, and the like.

In operation of the device, particulate material is charged into hopper 116 of coil feeder 34. The coal from the hopper 116 falls into the spaces 109 between the teeth 108 of rotary feeder wheel 106. As the feeder wheel the rotates it carries the coal particles down to the bottom of the coal feeder 34 adjacent the openings 144, 14% in wear plates 122, 124. At this point a blast of air entering through line 33 and connecting means 184 forces the coal out of the space 10? through connecting means 188 and into pipe line 40. The high pressure in pockets 1% of feeder wheel 103 is kept from passing through the feeder by means of the novel combination of sealing elements described above.

I claim:

1. A feeder for particulate material comprising a peripherally pocketed rotary feeder wheel with two sides mounted for rotation in an annular housing having a solids entrance, end plates to enclose the sides of said rotary feeder wheel, and two wear plates each having an annular U shoulder thereon, one wear plate being located between each of said end plates and said rotary feeder wheel, said annular shoulders of said wear plates abutting against said rotary feeder wheel, said wear plates and end plates having aligned air inlet and discharge openings in register with the pockets of the feeder wheel, and each of said wear plates and end plates further having an aperture therein for the insertion of sealing fluid into spaces formed between the sides of said feeder wheel and said wear plates, said rotary feeder wheel having an annular groove therein on each side thereof, each of said grooves being adapted to retain a seal ring therein, and a seal ring secured in each of said grooves, each of said seal rings having a flange adapted to effectively seal the space between said rotary feeder wheel and said annular shoulders of said wear plates, said flanges extending from said rotary feeder wheel across said annular shoulder, a spacer located inwardly of said flange of said seal ring, and an expandable ring spaced inwardly of said spacer, said expandable ring tending to expand and urge said spacer against said flange ll of said seal ring to urge said flange against said annular shoulder of said wear plate whereby said flange prevents leakage of high pressure air from said pockets of said rotary feeder wheel through said feeder.

2. A feeder for particulate material comprising a peripherally pocketed rotary feeder wheel with two sides mounted for rotation in an annular housing having a solids entrance, end plates to enclose the sides of said rotary feeder wheel, and two wear plates each having an annular shoulder thereon, one wear plate being located between each of said end plates and said rotary feeder wheel, said annular shoulders abutting against said rotary feeder wheel, said wear plates and end plates having aligned air inlet and discharge openings in register with the pockets of the feeder wheel, and each of said wear plates and end plates further having an aperture therein for the insertion of sealing fluid into spaces formed between the sides of said feeder wheel and said wear plates, said rotary feeder wheel having an annular groove therein on each side thereof, each of said grooves being adapted to retain a seal ring therein, and a seal ring secured in each of said grooves, each of said seal rings having a flange adapted to elfectively seal the space between said rotary feeder wheel and said annular shoulders of said wear plates, said flanges extending from said rotary feeder wheel across said annular shoulder, and an expandable ring spaced inwardly of each of said flanges, said expandable rings tending to expand and urge said flanges against said annular shoulders of said wear plates whereby said flanges prevent leakage of high pressure air from said pockets of said rotary feeder wheel through said feeder.

3. The apparatus of claim 2 wherein said seal ring is secured in position in said annular groove of said rotary feeder wheel by an annular bracket having an outer shoulder fltted over the body of said seal ring to prevent axial and radial movement of said seal ring relative to said rotary feeder wheel and a plurality of dowels inserted into said rotary feeder wheel through the body of said seal ring to prevent circumferential movement of said seal ring relative to said rotary feeder wheel.

4. A feeder for particulate material comprising a pcripherally pocketed rotary feeder wheel with two sides mounted for rotation in an annular housing having a solids entrance, end plates to enclose the sides of said rotary feeder wheel, and two wear plates each having an annular shoulder thereon, one wear plate being located between each of said end plates and said rotary feeder wheel, said annular shoulders abutting against said rotary feeder wheel, said wear plates and end plates having aligned air inlet and discharge openings in register with the pockets of the feeder wheel, and each of said wear plates and end plates further having an aperture therein for the insertion of sealing fluid into spaces formed between the sides of said feeder wheel and said wear plates, said rotary feeder wheel having an annular groove therein on each side thereof, each of said grooves being adapted to retain a seal ring therein, and a seal ring cemented in each of said grooves, each of said seal rings having a flange adapted to effectively seal the space between said rotary feeder wheel and said annular shoulders of said wear plates, said flanges extending from said rotary feeder wheel across said annular shoulder, and an expandable ring spaced inwardly of each of said flanges, said expandable ring tending to expand and urge said flanges against said annular shoulders of said wear plates whereby said flanges prevent leakage of high pressure air from said pockets of said rotary feeder wheel through said feeder.

5. In a feeder for particulate material wherein said particulate material is fed into the peripheral pockets of a rotary feeder wheel and said feeder wheel rotates to a position at which each pocket is emptied of its particulate material by a transverse blast of air through said pocket and wherein there are also provided wear plates and end plates positioned adjacent the sides of said rotary feeder wheel to enclose said rotary feeder wheel, the improvement comprising an annular groove in each side of said rotary feeder wheel, a seal ring secured in each of said grooves, each seal ring having a flange extending laterally therefrom beyond said groove in said rotary feeder wheel and adapted to seal the space between said rotary feeder wheel and said wear plate and two expandable rings, one expandable ring positioned in abutting relation with each of said flanges, said expandable rings tending to expand and urge said flanges of said seal rings against said wear plates whereby said flanges prevent leakage of high pressure air from said pockets of said rotary feeder wheel through said feeder.

6. In a feeder for particulate material wherein said particulate material is fed into the peripheral pockets of a rotary feeder wheel and said feeder wheel rotates to a position at which each pocket is emptied of its particulate material by a transverse blast of air through said pocket and wherein there are also provided wear plates and end plates positioned adjacent the sides of said rotary feeder wheel to enclose said rotary feeder wheel, the improvement comprising an annular groove in each side of said rotary feeder wheel, a seal ring cemented in each of said grooves, each seal ring having a flange extending laterally therefrom beyond said groove in said rotary feeder wheel and adapted to seal the space between said rotary feeder wheel and said Wear plate and two expandable rings, one expandable ring positioned in abutting relation with each of said flanges, said expandable rings tending to expand and urge said flanges of said seal rings against said Wear plates whereby said flanges prevent leakage of high pressure air from said pockets of said rotary feeder wheel through said feeder.

References Cited by the Examiner UNITED STATES PATENTS 2,173,247 9/39 Bott 277-l62 2,740,672 4/56 Morrow 30249 2,750,233 6/56 Yellott 30249 2,792,625 5/57 Hoffman 39--453 2,793,428 5/57 Witte 29-45 l FOREIGN PATENTS 664,893 9/38 Germany. HUGO O. SCHULZ, Primary Examiner. 

1. A FEEDER FOR PARTICULATE MATERIAL COMPRISING A PERIPHERALLY POCKETED ROTARY FEEDER WHEEL WITH TWO SIDES MOUNTED FOR ROTATION IN AN ANNULAR HOUSING HAVING A SOLIDS ENTRANCE, END PLATES TO ENCLOSE THE SIDES OF SAID ROTARY FEEDER WHEEL, AND TWO WEAR PLATES EACH HAVING AN ANNULAR SHOULDER THEREON, ONE WEAR PLATE BEING LOCATED BETWEEN EACH OF SAID END PLATES AND SAID ROTARY FEEDER WHEEL, SAID ANNULAR SHOULDERS OF SAID WEAR PLATES ABUTTING AGAINST SAID ROTARY FEEDER WHEEL, SAID WEAR PLATES AND END PLATES HAVING ALIGNED AIR INLET AND DISCHARGE OPENINGS IN REGISTER WITH THE POCKETS OF THE FEEDER WHEEL, AND EACH OF SAID WEAR PLATES AND END PLATES FURTHER HAVING AN APERTURE THEREIN FOR THE INSERTION OF SEALING FLUID INTO SPACES FORMED BETWEEN THE SIDES OF SAID FEEDER WHEEL AND SAID WEAR PLATES, SAID ROTARY FEEDER WHEEL HAVING AN ANNULAR GROOVE THEREIN ON EACH SIDE THEREOF, EACH OF SAID GROOVES BEING ADAPTED TO RETAIN A SEAL RING THEREIN, AND A SEAL RING SECURED IN EACH OF SAID GROOVES, EACH OF SAID SEAL RINGS HAVING A FLANGE ADAPTED TO EFFECTIVELY SEAL THE SPACE BETWEEN SAID ROTARY FEEDER WHEEL AND SAID ANNULAR SHOULDERS OF SAID WEAR PLATES, SAID FLANGES EXTENDING FROM SAID ROTARY FEEDER WHEEL ACROSS SAID ANNULAR SHOULDER, A SPACER LOCATED INWARDLY OF SAID FLANGE OF SAID SEAL RING, AND AN EXPANDABLE RING SPACED INWARDLY OF SAID SPACER, SAID EXPANDABLE RING TENDING TO EXPAND AND URGE SAID SPACER AGAINST SAID FLANGE OF SAID SEAL RING TO URGE SAID FLANGE AGAINST SAID ANNULAR SHOULDER OF SAID WEAR PLATE WHEREBY SAID FLANGE PREVENTS LEAKAGE OF HIGH PRESSURE AIR FROM SAID POCKETS OF SAID ROTARY FEEDER WHEEL THROUGH SAID FEEDER. 